Acid-curing thermosetting coating composition

ABSTRACT

A CATALYST THERMOSETTING COMPOSITION, USEFUL FOR COATINGS AND INKS, CONSISTING OF ONE OR MORE ACID-CURABLE RESINS AND AS A LATENT CATALYST COMPOSITION THEREFOR AN AMINO ALKANEDIOL HYDROCHLORIDE AND AN ALKANOLAMINE DISSOLVED IN A LOWER ALKANOL OR ETHERALKANOL. THE COMPOSITION HAS GOOD SHELF LIFE AND IS NON-CORROSIVE TO CONTAINERS. PREFERRED CATALYST COMPOSITIONS CONSIST OF 2-AMINO-2-ETHYL-1. 3-PROPANEDIOL HYDROCHLORIDE AND 2-AMINO-2-METHYL-1PROPANOL DISSOLVED IN ISOBUTYL ALCOHOL OR IN DIPROPYLENE GLYCOL MONOMETHYL ETHER.

United States Patent 3,810,853 ACID-CURING THERMOSETTING COATINGCOMPOSITION Frank James, Houston, Tex., and Richard A. Jones, TerreHaute, Ind., assignors to Commercial Solvents Corporation, New York,N.Y.

No Drawing. Original application Sept. 15, 1969, Ser. No. 858,102.Divided and this application July 24, 1972, Ser. No. 274,355

Int. Cl. C0911 3/52, 3/56, 3/66 U.S. Cl. 260-21 17 Claims ABSTRACT OFTHE DISCLOSURE This is a division of co-pending application Ser. No.858,102, filed Sept. 15, 1969.

BACKGROUND OF THE INVENTION This invention relates to a thermosettingcomposition useful for coatings and inks. In a particular aspect, itrelates to a catalyzed composition having good storage characteristicsand non-corrosive to containers.

The use of delayed curing, or latent, catalysts for acidcuringthermosetting resins has long been known. For example, Schroy, in U.S.Pat. 2,326,727 disclosed delayed curing thermosetting resins has longbeen known. For application to textiles. His catalysts were tertiaryamines or tertiary alkanolamines neutralized with organic or inorganicacids to a pH of 6-8. Upon heating to 140-150 C., the catalyst releasedthe acid portion of the salt causing the resin to cure rapidly. Primaryalkanolamines were not useful because the salts lacked the delayedaction characteristics of the tertiary amines and the resin curedrapidly at relatively low temperatures. However, Schroy disclosed thatsmall proportions of monoethanolamine could be substituted for anequivalent amount of triethanolamineto speed up the curing action of thelatter.

Foster et al., working with paper laminates of thermosetting aminoplastresins also taught, in U.S. Pat. 3,444,- 190, latent curing catalystsconsisting of tertiary alkanolamine salts of organic and inorganic acidsprepared by adding the acid to an aqueous solution of the amine to bringthe pH below 8.

The protective coatings industry has long used baking enamels based onresins having available hydroxy groups and acid-curing thermosettingresins, such as melamineformaldehyde and urea-formaldehyde resins, whichreact with the hydroxy groups at baking temperature. Although thereaction occurs slowly without the addition of an acid catalyst, thereaction is much faster in the presence of one, e.g. p-toluene sulfonicacid. This type of protective coating (hereinafter referred to ascoating) is prepared by dissolving the resins in a suitable solvent,then adding the pigment and any other desirable additives. Immediatelybefore use, the acid catalyst is added and the coating is applied to anarticle by spraying, brushing, dipping, etc., then heated to from 250 F.to 350 F. for a period of time sufficient to complete the polymerizationreaction. Similar formulations are used for thermosetting inks.

3,810,853 Patented May 14, 1974 Addition of the catalyst immediatelybefore use has been relatively successful but problems have arisen fromtime to time because the addition step is not under the control of themanufacturer of the coating and sometimes is improperly performed. Itwould be preferable to incorporate the catalyst in the enamel at thetime of manufacture, but this has previously been unsuccessful becausethe polymerization reaction proceeded gradually at room temperature, andthe preparation did not have a satisfactory shelf life. Furthermore theacid catalyst corroded the metal containers causing leakage and otherproblems. Accordingly a need has existed for a catalyst which can beincorporated in the thermosetting composition at the time ofmanufacture, yet be free from the problems of polymerization duringtransportation and storage and corrosion of the container.

SUMMARY OF THE INVENTION It is an object of this invention to provide animproved acid-curing, thermosetting composition useful for coatings andinks resins.

Another object of this invention is to provide a catalyzed,thermosetting coating having good storage characteristics andnon-corrosive to containers.

Other objects of this invention will be apparent to those skilled in theart from the disclosure herein.

The improved composition of the present invention consists essentiallyof one or more acid-curing resins, a resin containing available hydroxygroups reactable with the acid-curing resin, and a latent catalystcomposition. These components are dispersed in a suitable solvent systemalong with the pigment and any other desirable adjuncts known in theart. The latent catalyst composition consists of the hydrochloride saltof an amino alkanediol corresponding to Formula I N H: (I)

where R is methyl or ethyl, and an alkanolamine corresponding to FormulaII N R) 2 (II) where R is hydrogen or alkyl of 1 or 2 carbon atoms, andR is hydrogen, methyl or ethyl in a mole ratio of about 1.5-2.0 of theamino alkanediol per mole of alkanolamine, dissolved in a lower alkanolor ether-alkanol and having a pH of about 7.5 to 8.0. A process isprovided for the preparation of the preferred latent catalystcomposition which forms a part of the present invention.

DETAILED DISCUSSION The acid-curing thermosetting compositionscatalyzable by the latent catalyst composition of the present inventionare known in the art. The present invention provides an improvement overthe previous compositions in that the catalyst is incorporated thereinat the time of manufacture and surprisingly the resulting product can bepackaged, shipped and stored without the likelihood of gelling, i.e.polymerization, and without corrosion of the container as resulted frompreviously-used catalysts. Typical compositions have shown a packagestability of 6 months or more.

Typically, the composition of the present invention includes anon-volatile vehicle consisting of one or more acid-curing thermosettingresins and a resin having available hydroxy groups reactable with, andin a proportion by weight of about 3-4 parts to one of, the acid-curingresin. The resins are dispersed in a solvent mixture generallyconsisting of a mixture of one or more aliphatic alcohols, e.g. butylalcohol, an aliphatic hydrocarbon (e.g. varnish-makers and paintnaphtha) and an aromatic hydrocarbon, e.g. xylene. Pigments and otheradditives are added as desired. Compositions corresponding to theforegoing are known in the art and may be used in the practice of thepresent invention by the addition of the latent catalyst. Manyvariations are known and it is not intended that the invention belimited to any particular composition. The invention is broadlyapplicable to any coating or ink based on the resins recited herein.Additionally the composition preferably contains a minimum total butanolcontent-either a substantially pure isomer or mixture thereof--of 20% byweight, or more preferably, 25%. Many of the resins suitable for thepractice of the present invention are supplied in solution in butanol.

The latent catalyst composition of the present invention can be preparedby any suitable procedure, many of which will be apparent to thoseskilled in the art. For example, the amino alkanediol hydrochloride canbe prepared as a dry salt, then dissolved in a lower alkanol, e.g.methanol, or ether-alkanol and amino alkanol added thereto in a moleratio of about 056-058 of alkanolamine per mole of alkanediol. Thisamount is the approximate equivalent of the amount which, in an aqueoussystem, would provide a pH of about 7.5-8.0. The amount of alkanol isselected to provide a substantially homogeneous solution. The amountwill vary according to the components, generally more being requiredwith increasing molecular weight of the solid. A preferred catalystcomposition is one containing from about 17-22% by weight of aminoalkanediol hydrochloride and alkanolamine. Such a concentration cannotbe achieved by the foregoing procedure however, particularly with theuse of the preferred solvents such as isobutyl alcohol, nbutanol and theether-alkanols.

Accordingly the preferred catalyst compositions are prepared by thefollowing method which forms a part of the present invention. Thismethod is to dissolve an amino alkanediol represented by Formula I setforth above, or mixture thereof, in a lower aliphatic alkanol havingfrom 1 to 4 carbon atoms or in an ether-alkanol in a reaction vessel,preferably closed, equipped with an agitation means and a cooling means.Aqueous hydrochloric acid solution (36-38% concentration) or,preferably, anhydrous hydrogen chloride is gradually added through theinlet means until the pH is preferably, but not necessarily, within therange of 4.1-4.9, and a pH of 4.5 is particularly preferred. Whenanhydrous hydrogen chloride is employed, it is usually added by weightin an equi-molar amount equivalent to the amino alkanediol. However thepH can be monitored by periodically withdrawing samples, addingsufficient water to provide ionization, then obtaining a pH reading. Thereaction is exothermic and the cooling means is employed to maintain atemperature below 35 C., preferably below 30 C., to avoid deleteriousdevelopment of color. As the pH approaches 4.5 the rate of addition ofthe hydrochloric acid is slowed and, at about 4.5, the solution is heldunder continuous agitation until a constant pH reading is obtained,during which time the hydrogen chloride vapors above the surface of thesolution will be completely absorbed. An alkanolamine corresponding toFormula II is then introduced through the inlet means in a quantitysufficient to provide a pH within about 7.5-8.0 or, alternatively, in aratio of about 0.56-0.58 mole per mole of amino alkanediol.

The alkanolamine is liquid at ordinary temperatures and can be addedwithout dilution, or, if desired, it may be dissolved in a lower alcoholand added as a solution. The amount of HCl will vary slightly with theequivalent Weights of the amino alkanediol and the water content, ifany, will vary slightly with the HCl added.

The foregoing method of preparation is easily controlled and thecomposition, which has a solids content of about 19 to about 21%, and awater content of from zero to about 1-2% gives a consistent rate ofcure. Yet another method is dissolve the amino alkanediol and thealkanolamine in a mole ratio of about l.5-2:1 in-the solvent, i.e. alower aliphatic alkanol or an ether-alkanol in a weight ratio of fromabout 50-80 parts of solvent per part of the amino alkanediol and addthereto hydrochloric acid solution (36-38%) or anhydrous hydrogenchloride in a stoichiometric amount equivalent to the amount of aminoalkanediol present, i.e. in about a 1:1 mole ratio.

The catalyst composition which forms a part of the present invention canbe mixed with the acid-curing thermosetting composition, i.e. thecoating or ink, shortly before use in accordance with the prior art.However, to obtain the particular benefits of the invention, thecatalyst composition is mixed with the coating or ink prior topackaging. The amount used may be selected according to the anticipatedrate of cure desired and the temperature intended to be employed. Thehigher the catalyst concentration and/or the higher the temperature, thefaster the rate of cure will be. Generally the catalyst composition,which is about 20% solids, is used in an amount sufiicient to providefrom 220% by weight of the catalyst solution, prepared as hereinbeforedescribed, based on the Weight of the total non-volatile vehicle in theacid-curing composition, equivalent to 0.4-4.0% by Weight of thecatalyst solids. For most resin combinations, however, from 3-7% of thesolution equivalent to about 0.6-1.4% by Weight, based on the weight ofthe non-volatile vehicle, will be most commonly employed, and about 5%by weight of solution, equivalent to about 1% by weight of solids, isgenerally preferred. The term, non-volatile vehicle as used hereindenotes the total resin components, i.e. the acid-curing resin orresins, and the resins having available hydroxy groups reactable withthe aforesaid acid-curing resins.

The term acid-cure as used herein is commonly understood by thoseskilled in the art to mean that the polymerization proceeds tocompletion. The term curing time is used herein to indicate the timerequired to obtain a satisfactory hardness of the coating. The termacid-curing thermosetting resin includes those resins which may be curedonly under acid conditions and also those which may be cured undereither acid or alkaline conditions. Such resins include those obtainedby reacting an aldehyde, e.g. formaldehyde, acetaldehyde, benzaldehyde,etc., with one or more of the following: urea, thiourea, the reactionproducts obtained by heating and decomposing dicyandiamide, melamine,other aminotriazines, phenol, other phenols such as the alkyl phenols,etc. Mixed resins, e.g. urea-melamine-formaldehyde resins,urea-thioureaformaldehyde resins, etc. may be prepared by reacting thealdehyde with each of the other reactants separately or the aldehyde maybe reacted with a mixture of other reactants. Mixed resins containingfrom about 20%-60% melamine-formaldehyde resin and the remainderureaformaldehyde resin are especially useful.

The foregoing acid-curing thermosetting resins are used in conjunctionwith resins having available hydroxy groups reactable with theacid-curing resins. Cross-linking occurs between these two types ofresins during the heating step. Resins having available hydroxy groupsinclude alkyd resins, polyvinyl alcohol and copolymers thereof,polyurethanes, and polyesters such as polyacrylates. These resins areused in the same proportions with the thermosetting resins as previouslyknown in the art. Generally the proportions are in the range of 2-4 toone of acidcuring resin, by weight.

The amino alaknediols suitable for the practice of this inventioninclude, but are not limited to, 2-amino-2-methyl-1,3-propanediol andpreferably 2-amino-2-ethyl-1,3- propanediol because it generally gives afaster cure and is more compatible with most resins than the methylhomolog. Other amino alkanediols can also be used and they are regardedas obvious equivalents of the preferred compounds. Mixtures of aminoalkanediols are also suitable for the practice of this invention.Products of good quality are preferred to avoid color development duringthe baking step.

The alkanolamines suitable for the compositions of the present inventioninclude, but are not limited to, monoethanolamine,2-amino-2-methyl-l-propano], 2-amino-1- butanol and the N,N-dimethylderivatives of these compounds, as well as mixtures thereof. Otherprimary and tertiary alkanolamines can also be used and are regarded asobvious equivalents of the preferred alkanolamines. The preferredalkanolamine is 2-amino-2-methyl-1-propanol. Products of good qualityare preferred to avoid color development during the baking step. Theterm alkanolamine as used herein is intended to mean monoamino,monohydroxy and substituted alkanes. The amino substituent can also besubstituted with alkyl, e.g. methyl, groups.

The solvents suitable for preparing the catalyst combination of thepresent invention include ether-alkanols and lower alkanols having from1 to 4 carbon atoms, e.g. methanol, ethanol, isopropyl alcohol,n-propanol, n-butanol, isobutyl alcohol and secondary butyl alcohol.When ethanol is used, either the 95% or anhydrous material is suitable,but anhydrous is preferred. When isopropyl alcohol is used, either the99% or the anhydrous material is suitable. Of these lower aliphaticalcohols, isobutyl alcohol is preferred.

Suitable ether-alkanols correspond to the formula R 0-*(CH CH -OH whereR is an alkyl group of from 1 to 4 carbon atoms or the group where R ismethyl or ethyl and where x is an integer of 1 or 2. Such ether-alkanolsinclude the glycol ethers, i.e. the methyl, ethyl, propyl and butylmono-ethers of ethylene and propylene glycols, and the methyl and ethylethers of diethylene glycol and dipropylene glycol or mixtures thereof.These ether-alkanols are particularly useful when the acid-curingcomposition is intended for use as an ink, and dipropylene glycolmonomethyl ether is particularly preferred.

The amount of solvent used may vary somewhat depending on the particularsolvent and the components used. Generally an amount of solvent isselected to provide a homogeneous solution of the amino alkanediolhydrochloride and the alkanolamine. If a phase separation occurs duringthe preparation of the catalyst composition, additional solvent can beadded to provide a homogeneous solution. The optimum amounts can bereadily determined by those skilled in the art, but generally from 3-5parts by weight of solvent per part of total solids; i.e. the combinedamino alkanediol, aminoalkanol and hydrogen chloride, anhydrous basis,is sufiicient, and a ratio of 4:1 is preferred. When the amount ofsolvent differs significantly from a ratio of 4:1, then the amount ofcatalyst solution added to the coating must be adjusted to provide asuitable concentration.

The composition also contains some water from the hydrochloric acidsolution when the solution is used. Generally the volume usuallyinvolved is tolerable but preferably the amount of water present is suchthat it does not separate after the catalyst has been incorporated inthe baking enamel. When water is undesirable, anhydrous 6 hydrogenchloride should be used for preparing the catalyst.

EXAMPLE 1 2-amino-2 ethyl 1,3 propanediol, g. (about 0.7 mole), having aneutralization equivalent of 121.6, was delivered to a closed reactionvessel equipped with an agitation means, a thermometer, a pH monitoringmeans, a cooling means, and an inlet means. There was added 567.5 g. ofisobutyl alcohol and the mixture was agitated until the alkanolamine hadcompletely dissolved. The cooling means was adjusted to maintain atemperature of 30 C. or below. Concentrated hydrochloric acid (36- 38%commercial grade) was gradually added with agitation until a pH of 4.5was obtained. About 26 g. of HCl, anhydrous basis (70 g. of solution)was added. The agitation was continued for about an hour during whichtime hydrogen chloride vapors above the surface of the liquid wereabsorbed and the pH reading was constant. The cooling means was adjustedas required to maintain a temperature of below about 30 C. There wasthen added 35 g. (about 0.4 mole) of 2-amino-2-methyl-l-propanolresulting in a pH within 7.5-8.0. The solution thereby obtained wascolorless and had a specific gravity of 0.875 at 25/ 25 C. The solidscontent was about 19% by weight and water content was 5.8%.

The catalyst was then used in a conventional baking The above pigmentmixture was ground in a mill until the pigment was completely dispersed.The alkyd resin used was Duramac 2483, a short oil baking-type alkydmade from tall oil fatty acids and manufactured by Mc- WhorterChemicals-Company, Maywood, Ill.

The pigment mixture was then used to prepare a baking enamel bydispersing in a mixture prepared with the fol- The melamine-formaldehyderesin used was Cymel 248-8 obtained from American Cyanamid Company, NewYork, NY. and the butylated urea-formaldehyde resin was Beetle resin XB1032, also manufactured by American Cyanamid Company. The weights givenfor the above resins include the solvents in which the resins aredissolved as marketed. To the above mixture was added 15.6 g. of thecatalyst composition, or 3.0 g. dry basis, to provide a concentration ofabout 5.2% based on total non-volatile vehicle. This baking enamel withpre-packaged catalyst was determined to have suitable shelf life and themetal container was free from corrosion.

The enamel prepared above was applied to metal articles. One article wasbaked at 250 F. and satisfactory hardness was achieved in 15 minutes. Asecond coated article was baked at 300 F. and in 10 minutes had achievedsatisfactory hardness. An article coated with an enamel similar to theforegoing except containing neither catalyst nor melamine resin required30 minutes baking time at 350 F.

7 EXAMPLE 2 The experiment of Example 1 was repeated except that 7%catalyst was added to the coating composition. At 250 F, a satisfactorycure was obtained in 10 minutes and at 300 F. only minutes was required.When the above experiment was repeated at 5% catalyst and 250 F. bakingtemperature, a curing time of 15 minutes Was required. When theurea-formaldehyde resin was baked without a catalyst present, itrequired 30 minutes curing time at 250 F. and 15 minutes curing time at300 F.

EXAMPLE 3 The experiment of Example 1 is repeated except that2-amino-2-methyl 1,3 propanediol is substituted for 2- amino-2-ethyl 1,3propanediol and isopropyl alcohol is substituted for isobutyl alcohol.The resulting catalyst composition is incorporated in an enamel based onacidcuring resins. The packaged enamel has a satisfactory shelf life,does not corrode the container and when applied to an article andheated, it cures rapidly.

EXAMPLE 4 The experiment of Example 1 is repeated except thatZ-amino-l-butanol is substituted for 2-amino-2-methyl-1- propanol andethanol is substituted for isobutyl alcohol. The resulting catalyst,when added to a baking enamel based on an acid-curing resin, provides acomposition having good shelf life, is not corrosive to metalcontainers, and cures rapidly at elevated temperatures.

EXAMPLE 5 The experiment of Example 1 is repeated except thatmonoethanolamine is substituted for 2-amino-2-methyl-1- propanol andmethanol is substituted for isobutyl alcohol. The resulting catalyst,when added to a baking enamel based on an acid-curing resin, provides acomposition having good shelf life, is not corrosive to metalcontainers, and cures rapidly at elevated temperatures.

EXAMPLE 6 The experiment of Example 1 is repeated except thatN,N-dimethyl-2-amino-2-methyl-l-propanol is substituted for2-amino-2-methyl-l-propanol and n-butanol alcohol is substituted forisobutyl alcohol. The resulting catalyst, when added to a baking enamelbased on an acid-curing resin, provides a composition having good shelflife, is not corrosive to metal containers, and cures rapidly atelevated temperatures.

EXAMPLE 7 The experiment of Example I is repeated except thatN,N-dimethyl-2-amino-l-butanol is substituted for 2-amino-Z-methyl-l-propanol and sec.-butanol is substituted for isobutylalcohol. The resulting catalyst, when added to a baking enamel based onan acid-curing resin, provides a composition having good shelf life, isnot corrosive to metal containers, and cures rapidly at elevatedtemperatures.

EXAMPLE 8 The experiment of Example 1 is repeated except thatN,N-dimethyl-monoethanolamine is substituted for 2-amino-Z-methyl-l-propanol. The resulting catalyst, when added to abaking enamel based on an acid-curing resin, provides a compositionhaving good shelf life, is not corrosive to metal containers, and curesrapidly at elevated temperatures.

8 EXAMPLES 9-14 The experiment of Example 1 was repeated using severaldifferent melamine and urea resins. The compositions coresponded to theformulas tabulated below. The weights given for the ingredients includesolvents in which the resins are dispersed as marketed. The catalystlevel, or concentration, varied from 35% by weight of solution,equivalent to 0.58-0.96% by weight of solids based on the weight ofnon-volatile vehicle.

Example No.

Ingredients, lbS.:

Pigment k 25 l 250 i 250 i 250 m 200 Alkyd resin L... 450 450 450 450450 Melamine resin b 55 55 120 50 Urea resin 9O 90 Butanol. 50 50 50 5050 Naphtha 58 53 63 63 53 Xylene 62 32 28 38 36 Catalyst.... 9 14. 7 14.7 8.5 14. 7 Viscosity, seem... 23 28 22 26 25 Density, lbs/gal 8. 0 9.95 9. 76 9. 79 9. 44 Total solids, percent wt 55.6 39.6 55.3 54.8 54.652.65 Non-volatile vehicle:

6 75 75 79 79 75. 6 Melamine, percent w 9. 3 10 10 21 9. 3 Urea, percentwt 15. 1 15 15 21 15. 1 Catalyst level, percent wt 5.0 3.0 4 9 5.2 3 5Baking time, at-

250 F., min 12 15 10 10 15 12 350 F., min 2 2 2 2 2 2 Duramac-2483, ahigh viscosity, short oil baking alkyd made from tall oil fatty acids,50% solids in xylol and having an acid number of 4; manifacltured byMcWhortcr Chemicals 00., Maybrook Square, Maywoo I b CymeImelamine-formaldehyde resin 248-8, 55% by wt. in 1 :1 butanol-Ixqylxezne solvent; manufactured by American Cyanamid 00., New York,

Plaskon butylated urea-formaldehyde resin 3353, 50% solids by wt, i1i413:2 butanol-xylene solvent; manufactured by Oarglll, Inc., Minneapolisinn.

d Varnish-makers and paint naphtha.

@ Ford cup No. 4.

1 Solution prepared according to Example 1; percentage based on totalnon-volatile vehicle.

8 Uformite F200E, butylated urea-formaldehyde resin, 50% solids by wt.in butanol; manufactured by Rohm and Haas 00., Philadelphia, Pa.

Uformite MM-55 melamine-formaldehyde coating resin, 50% solids inbutanol; manufactured by Rohm and Haas 00., Philadelphia, Pa.

i Beet XB-1032 butylated urea-formaldehyde coating resin, 50% solids inisobutyl alcohol; manufactured by American Oyanamid 00., New York, N.Y.

Titanium dioxide.

P Al1ur2ninmn paste, MO-588 marketed by Alcan Sales, Pittsburgh Chromeyellow, HY-Cap Y-469, manufactured by E. I. du Pont de N emours, Inc.,Wilmington, Del.

m Molybdate orange, Saltex Ming Orange Dark 2522-03, marketed by theHarshaw Chemical 00., Cleveland, Ohio 44106.

EXAMPLES 15-18 The formulations tabulated below are additional examplesof different types of reactable reins having available hydroxy groupsreactable with the acid-curing thermosetting resins. The catalyst wasprepared according to claim 1 and varied from 7 .4-20% by weight of thesolution, equivalent to l.4-3% by weight of solids based on the weightof non-volatile vehicle.

The coating of Example 15 was notable for its high abrasion resistanceand that of Example 16 was notable for its excellent hardness,flexibility and corrosion resistance.

The coating of Example 17 was suitable as a primer for wood orcomposition board.

The coating of Example 18 is an aqueous system. The ingredients weredispersed in butoxy ethylene glycol 35 1b.; water, 1b.; aqua ammonia(28%), to pH 8.6, 13 1b.; Dow-Corning DC-ll silicone anti-foam agent, 31b.

Example No.

Urea resin Acrylic resin Melamine Xylene; Ethoxyethyl acetate Density,lbs/gal Total solids, percent w Baking schedule, min.l F 2 v Heliol2o4-2 thermosetting urethane resin,- 70% solids in ethoxyethyi ibcetate,manufactured by Wilmington Chemical Corp., Wilmington,

Acryloid AT-56, esters of acryl and methacrylic acid, hydroxylfunctional type thermosetting acrylic resin, 50% solids in 90:10xylenebutanol solvent, manufactured by Rohm and Haas 00., Philadelphia,

P Duramac 2482 alkyd resin, a pure short oil alkyd, tree from rosin orcopolymers; manufactured by McWhorter Chemicals -Co., Maybrook Square,Maywood, Ill.

Polyvinyl chloride alcohol-acetate terpolymer, Bakelite VAGH,manufactured by Union Carbide Corp., New York, N.Y.

ymel 350 melamine resin, 98% manufactured by American Cyanamid 00., NewYork, N.Y. p

I Aquamac-1065 water-soluble oxazollne alkyd resin, 65% in aqueousisobutyl alcohol; manuiactured by McWhorter Chemicals Co., MaybrookSquare, Maywood, 111.

I Titanium dioxide, 216 lbs.; barytes, 108 lbs.; talc, 54 lbs.

EXAMPLE 19 EXAMPLE 20 The experiment of Example 19 is repeated exceptthat l-methoxy-Z-ethanol is substituted for dipropylene glycolmonomethyl ether. It is used in the preparation of a thermosetting ink.

EXAMPLE 21 The experiment of Example 19 is repeated except thatl-ethoxy-Z-ethanol is substituted for dipropylene glycol monomethylether. It is used in the preparation of a thermosetting ink.

EXAMPLE 22 The experiment of Example 19 is repeated except thatl-propoxy-Z-ethanol is substituted for dipropylene glycol monomethylether. It is used in the preparation of a thermosetting ink.

EXAMPLE 23 The experiment of Example 19 is repeated except thatl-butoxy-Z-ethanol is substituted for dipropylene glycol monomethylether. It is used in the preparation of a thermosetting ink.

EXAMPLE 24 The experiment of Example 19 is repeated except that1'methoxy-3-propanol is substituted for dipropylene glycol monomethylether. It is used in the preparation of a thermosetting ink.

EXAMPLE 25 The experiment of Example 19 is repeated except that1-ethoxy-3-propanol is substituted for dipropylene glycol 10 monomethylether. It is used in the preparation of a thermosetting ink. EXAMPLE 26The experiment of Example 19 is repeated except that dipropylene glycolmonoethyl ether is substituted for dipropylene glycol monomethyl ether.It is used in the preparation of a thermosetting ink.

EXAMPLE 27 The experiment of Example 19 is repeated except thatdiethylene glycol monomethyl ether is substituted for dipropyleneglycol'monomethyl ether. It is used in the preparation of athermosetting ink.

EXAMPLE 28 The experiment of Example 19 is repeated except thatdiethylene glycol monoethyl ether is substituted for dipropylene glycolmonomethyl ether. It is used in the preparation of a thermosetting ink.

EXAMPLE 29 The experiment of Example 1 is repeated using about 670 partsby weight of isobutyl alcohol per parts of amino alkanediol and using37% aqueous hydrochloric acid'solution, 82.5 parts containing water,about 50 parts by weight.

' EXAMPLE 30 The experiment of Example 1 is repeated except that about720 parts by weight of isobutyl alcohol is employed and the hydrogenchloride is anhydrous.

We claim:

1. An acid-curing thermosetting composition having good storagecharacteristics and being non-corrosive to steel containers consistingessentially of (a) an acidcuring, thermosetting resin selected from thegroup consisting of aldehyde-ureas, aldehyde-aminotriazines,aldehyde-phenols and mixtures thereof, (b) a resin selected from thegroup consisting of polyvinyl alcohol and copolymers thereof,polyurethane, polyacrylates and other polyester resins having availablehydroxy groups reactable with said acid-curing resin in a ratio of about2-4 to one of said acid-curing resin, by weight, and (c) from 2-20% byweight of a latent catalyst composition consisting of from about 17-22%by weight of an aminoalkanediol hydrochloride and an alkanolamine in amole ratio of about 1.5-2.0:1 respectively dissolved in a lower alkanolhaving from 1 to 4 carbon atoms or in an etheralkanol saidaminoalkanediol corresponding to the formula where R is methyl or ethyl,said alkanolamine corresponding to the formula R2 IU-C-CHzOEi wherein Rand R are hydrogen, methyl or ethyl.

Z. The composition of claim 1 wherein said amino alkanediol is 2 amino2-methyl-1,3-propanediol or 2- amino-Z-ethyl-1,3-propanediol or amixturethereof.

3. The composition of claim 1 wherein said alkanolamine is selected fromthe group consisting of 2-amino-2- methyl l propanol, 2 amino-l-butanol,monoethanolamine and the N,N-dimethyl derivatives thereof and mixturesthereof.

4. The composition of claim 1 wherein said catalyst solution is presentin an amount of about 3-7% by weight.

5. The composition of claim 1 wherein said catalyst solution is presentin an amount of about 5% by weight.

6. The composition of claim 1 wherein said catalyst solution containsfrom 19-21% by weight of aminoalkanediol hydrochloride and alkanolamine.

7. The composition of claim 1 wherein said thermosetting resin is aurea-formaldehyde resin.

8'. The composition of claim 1 wherein said thermosetting resin is aphenol-formaldehyde resin.

9. The composition of claim 1 wherein said thermosetting resin is anaminotriazine-formaldehyde resin.

10. The composition of claim 1 wherein said resin having availablehydroxy groups is an alkyd resin.

11. The composition of claim 1 wherein said resin having availablehydroxy groups is a polyvinyl alcohol resin.

12. The composition of claim 1 wherein said resin having availablehydroxy groups is a copolymer of polyvinyl alcohol.

13. The composition of claim 1 wherein said resin having availablehydroxy groups is a polyurethane resin.

14. The composition of claim 1 wherein said resin having availablehydroxy groups is a polyester resin.

15. The composition of claim 14 wherein said polyester resin is apolyacrylate resin.

16. In a composition based on an acid-curing thermosetting resin ormixtures thereof and a resin having available hydroxy groups reactablewith said acid-curing resin as the non-volatile vehicle, saidcomposition having good storage characteristics and being non-corrosiveto steel containers, the improvement consisting essentially of using220% by weight of a catalyst composition for curing said acid-curingresin consisting of from about 17-22% by weight of an aminoalkanediolhydrochloride and an alkanolamine in a mole ratio of about 1.52.0:1,respectively dissolved in aqueous-lower alkanol having from 1 to 4carbon atoms and having a pH of from 7.5 to 8.0, said amino alkanediolcorresponding to the formula R HO CHz-E-CHzOH where R is methyl orethyl, said alkanolamine correspond ing to the formula wherein R and Rare hydrogen, methyl or ethyl.

17. The composition of claim 16 wherein said catalyst composition ispresent in an amount of from about 0.4 to 4% by weight of solids basedon the weight of said nonvolatile vehicle.

References Cited UNITED STATES PATENTS MAURICE I. WELSH, PrimaryExaminer R. W. GRIFFIN, Assistant Examiner US. Cl. X.R.

117-132 BF, 161 K, 161 L; 252-429; 260-20, 22 CQ, 33.6 UB, 33.6 UA, 842,844, 850, 856, 849

(223? UNITED STA'ETES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3 310 353 Bat-ed MEN! l4 1974 In n flflflan lL lame-s and Richard A.Jones It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Column 1, line 38 should read --curing catalysts for acidcuringjthermosetting resins for-- Column 4, line ll, following the word "is"insert -to- Column 5, line 3, "alaknediols" should be -alkanediols'-Column 6, line 43, "Chemicals-"Company" should be --Chemical Company--Column 8, line. 59, "reins" should be --resins-. Column 9, line l4, inthe table, "Catalyst f" should be -Catalyst-- Signed and sealed this 5thday of November 1974.

(SEAL) Atteet I McCOY M. GIBSON JR C. MARSHALL 'DANN Attesting OfficerCommissioner of Patents

